How does yoga affect brain structure and function?
Research Study At A Glance
The Research Question Asked
Does yoga affect brain structure and function?
Type of Study
Case control study
Study Participants (Sample)
The sample of participants included 26 total participants organized into 13 matched pairs: a yoga treatment group and a control group. Those in the yoga treatment group had practiced yoga at least three times per week for at least three years. Those in the control group had no prior experience with yoga.
Study participants in both the treatment and control groups completed the Sternberg working memory task, a cognition and memory test, while receiving a functional MRI scan. The volume of gray matter (a type of brain tissue) in several areas of the brain (the hippocampus, thalamus, and caudate nucleus), as well as speed and accuracy while completing the test, were compared between the treatment and control groups.
Yoga practitioners had greater gray matter volume (a type of brain tissue) in their left hippocampus and had a higher activation level of the dorsolateral prefrontal cortex during a particular part of the Sternberg task.
Yoga does positively affect brain structure and function.
Previous research found that yoga affects not only physical health attributes, like flexibility and strength, but it also suggests that yoga affects brain structure and function. Some previous studies found that yoga positively affects attention, executive function (mental processes involved in planning and making decisions), and memory, as well as other traits, when compared to control participants. These functions of the mind happen in different areas of the brain. Researchers more recently have just begun to take a look at whether doing a yoga practice actually changes the appearance or structure of the areas of the brain where these mental functions happen.
Does yoga affect brain structure and function?
This experiment was a case control study. It used a type of experimental design called randomized block design with matched pairs. Each of the 13 participants in the yoga treatment group was matched with a control participant of the same age and sex. Both groups completed psychosocial and demographic questionnaires so researchers could confirm that the two groups were similar. The researchers then conducted a 6-minute walk test to test for general physical activity level. They confirmed that VO2 max (a measurement of oxygen consumption during exercise) and basic physical fitness level were not significantly different for the yoga group and control group.
After establishing that participants in the yoga treatment group and the control group were similar with respect to demographics and general physical fitness, they all completed the Sternberg working memory task while having a functional MRI scan. The Sternberg working memory task is a cognition and memory test where participants are briefly shown a group of four letters and then must quickly report whether a single letter, shown after the group of four letters, was present in the original group. The Sternberg working memory task tests participants on several aspects of mental function, including: attention, reaction time, and memory.
Researchers then compared those in the yoga treatment group with those in the control group and looked for any differences in brain structure, specifically measured as difference in gray matter (a type of brain tissue) and volume of the hippocampus, thalamus, or the caudate nucleus, which are three different regions found in the brain. They also compared the brain activation of the two groups during the Sternberg working memory task.
It does seem that yoga affects brain structure and function, as researchers found significant differences in brain structure and function between the yoga treatment group and the control group. Yoga practitioners had greater gray matter volume in their left hippocampus and had a higher activation level of the dorsolateral prefrontal cortex (a region in the brain associated with attention and memory) during a particular part of the Sternberg task. There were no differences in reaction time or accuracy on the Sternberg task between the yoga treatment group and the control group.
Why is this relevant to yoga practitioners?
As yoga practitioners, we’re likely already aware that yoga makes us feel better. That’s why we do yoga, right? We might even have noticed that when we practice yoga we feel like our attention and concentration on other things in our life, like our work, are better too. When researchers explore why and how these benefits of yoga occur, they provide information about potentially how we can use yoga practice more effectively to generate these benefits. The results of their experiments can tell us more about what changes are actually happening in our brain and body when we experience the benefits of yoga, like increased attention. Learning more about what the potential benefits of yoga practice are, might also help motivate us to practice!
Gothe, N.P., J.M. Hayes, C. Temali, and J. S. Damoiseaux. 2018. Differences in brain structure and function among yoga practitioners and controls. Frontiers in Integrative Neuroscience. 12:26. doi: 10.3389/fnint.2018.00026.